Torque measuring wrench



g- 1939- H. w. ZIIMMERMAN 2,169,673

TORQUE MEASURING WRENCH Filed April 12, 1957 2 Sheets-Sheet 1 M1; i H. w. ZIMMERMAN TORQUE MEASURING WRENCH Filed April 12, 1957 2 Sheets-Sheet 2 Jm%mw fifiizaiz ff zmzmerman arse STATES TORQUE *MEASURING WRENCH Herman W. Zimmerman, Highland Park, 11]., as-

signor, by mesne assignments, to Frederick G. I Wacker and Grace J. Wacker, Lake Forest, 11].

Application April 12, 1937, Serial No. 136,307-

- 8 Claims.

My invention relates to wrenches, and it has to do more particularly-with a wrench for measuring the force or torque applied thereto in tightening or loosening nuts, bolts, studs, and the like.

One of the objects of 'my invention is to provide an improved torque measuring wrench which is of simple and inexpensive construction and is adapted to operate efiiciently at all times.

Another object is to provide a torque measuring wrench having a hand grip unit' embodying means through which the torque measuring function is performed.

A further and more specific object is to provide a wrench of the foregoing character embodying a. handle movably supporting a grip member, means opposing movement of the gripmember relative to thehandle and whichis adapted to give way permitting such relative movement when the resistance'ofiered by Hie work becomes such as to require the application of a predetermined amount of force or torque to overcome the same, and means for measuring the extent of relative movement of the grip member.

Other objects and advantages will become aperence to the drawings whereint Figure 1 is a side elevational view of one'form of wrench structure embodying my invention;

Fig. 2

Fig. 1;

parent as this description progresses, and by ref- Fig. 3 'is an enlarged top plan view partially in section of the hand-grip-end portion of the structure-of 2; r

Fig, 4 isa section takensubstantially on the line 4--4. of Fig. 3;

Fig. 5 is a top plan view, partially in section,

of another form of wrench structure embody ingmy invention;

Fig. 6 is a viewtaken substantially on the line 5-4 of Fig. 5; and

\ Fig. 7 is an enlarged side elevational view of,

portionof the structure t e work-engaging end of [Fig 5. v

Referringto the structure shown in Figs. 1 to 4, inclusive, it includes a handle In having, at its forward end, a cylindrical head ll fixedly slip-J porting an adapter element I2 which is suitably constructed and arranged for support of any suitable adapter device, (not shown) for engaging various kinds of work (nuts, bolts, studs and the like devices) The handle l further supports, at its rear end, a hand, grip unit embody- 55 ingmy invention, this unit is adapted to be is a top plan view .of the structure of grasped by the operator in using the wrench to tighten or loosen the work. I

The hand grip unit includes an enlarged integral (preferably but not necessarily rectangular) body portion l3 at the rear end of the handie, and it slidably supports a two-was grip member M for movement toward and from the axis of the handle l0. Specifically, the grip member includes a pair of grip elements 14 and l4 connected together in opposed, spaced relation by a pair of longitudinally spaced slide-stud members l and it. These slide studs, as shown in Figs. 1 and 2, extend through the body portion l3 at right angles to the axis of the handle in a plane -at right angles to the axis of the head II and the work; whereby the forces'applied to the grip elements are exerted normally and completely in a rotary direction upon-the work. The outer surfaces of the grip elements l4 and N are slightly rounded or otherwise shaped to permit the same to be conveniently grasped by the hand mined initial force or torque must be applied to the grip elements in order to initially overcome the spring means to efiect relative movement of the grip unit and handler-To this end, the body I3 is provided with opposed pairs of recesses l9v axially aligned with the slide studs l5 and I6, and coil springs 20, 2| and 22, 23, all preferably of like construction, are seatedin the recesses IS. The springs 20 to 23, inclusive, areof suchlength as to be confined between the hand grip elements l4 and l4 and the body l3, either under'slight compression'or so arranged that the grip elements l4 and M are held in abalanced or central or equally spaced position relative to the axis of the handle. With this arrangement, when the wrench is applied to the work in an upright condition'and it is rotated in clockwise direction (asviewed in Fig.2) to tighten the work, the springs 20'and 22 oppose relative movement between the grip unit. Hi and the body l3 of the handle l0. However, as soon as the work oflers sufiicient resistance to overcome the initial tension of the springs 20 and 22, such springs will begin to compress, and to an extent dependent upon the amount of force or torque applied, and movement of the grip 'eie- I .by a rack member 24.

take place. Assuming that the wrench is applied to the work in the same upright position and is moved in the opposite direction to loosen the work, the springs 2i and 23 function similarlyto the springs 28 and 21 and movement of the grip element i4 toward and relative to the body I: will take place so long as the work ofiers a resistance suilicient to overcome the initial tension or the spring It will be seen from the foregoing that a certain amount of force or torque must be applied to the work through the grip unit in order to initially compress either the springs 28, 22 or 2|, 23, and that the extent of compression of such springs and, in turn, the extent of relative movement of the'grip elements i4 and i4 depends upon the amount of force or torque applied to the work. In carrying out, my invention, I provide means for measuring the extent of movement of the grip unit i4 in either direction in terms of inch-pounds pressure so that the operator may readily determine when any particular piece of work is tightened to a desired extent,

and also when a series of pieces of work are tightened to a uniform extent.

In carrying out the foregoing, the forward ends "of the grip elements 4- and i4 are bridged The ends of this rack are secured to the ends of the grip elements i4 and l4 by fastening devices 25 and such rack is provided with shoulder elements 25 at its oppo-' site ends that engage the inner faces of the r p elements l4 and so as to brace the rack against torsional strains and stresses that may be imposed thereon during operation. The slide studs i5 and it may be so connected to the hand grip elements i4. and i4 as to fixedly hold them in a predetermined spaced relation,

or the springs 28 to 23, inclusive, together with the rack 24, may serve this purpose.

The rack 24 operatively engages a pinion 21 which is rotatably mounted on the handle II by a shaft-like pin 21. The pinion 21 supports a gage hand 28 which. is movable, through the movement of the rack'and pinion structure; relative to an elongated scale member 28 fixedly secured to'the handle I! in a plane substantially parallel to the plane of the movement of the pinion and gage hand --28. The member 28 is provided with a scale 38 calibrated to re ister inch-pounds pressm'e. In the operation of this structure, relative movement ofthe grip element 14': toward the handle I. actuates the gage hand 28, through therack and pinion structure, in clockwise direction as viewed in Fig. 3. 'Th gage hand ismoved in-the opposite direction when tne grip element i4 is moved toward the handle. In both instances, the extent of movement of the gage hand away from the zero mark of the scale 38 indicates, in terms or inch-pounds pressure, the force or torque applied tothe work through the grip unit i4.-

In Figs. 5 to 7, inclusive, I have shown another form of structure well adapted for carrying out my invention. This structure is somewhat sim-' ilar to that previously described, except that movement of the grip unittoward the handle is opposed by hydraulic means instead of spring means. Specifically, this structure (Fig. 5) includes a handle 48 supporting atits forward end a-wrench head 4i. This'wrench head isprovided with an adapter element 42 to which any suitable adapter device may be attached for engagement with the particular work to be tightened. The rear end hydraulic gripunit 43 which will now be described.

of the handle "supports a to the grip elements i4 and I4 The grip element 45 is provided with a pair of longitudinally spaced. piston-like supports 46 and 41 which are snugly and slidably received in aligned piston chambers 48 and 48 formed in the body portion 44 of the grip unit. The forward ends of the piston supports 46 and 41 are provided with packing means 50 such as may be required for a hydraulic operation. The chamber 48 is connected with a hydraulic gage structure 5i oi! any well-known form, such as the Bourdon tube type, by the passages 52 and 53 in the ,body 44. The chamber 58 is likewise connected to .the

' gage 5i by a passage 54 and the passage 53. The

hand ii and a scale 5i with respect to whichthe hand 5i is movable. This structure is so arranged that displacement of the fluid in the chambers 48 and 49 will cause movement of the gage hand clockwise relative to the scale 5|, and the extent of this movement depends upon the extent of displacement of the fluid. The fluid in the chambers 48 and 49 is displaced by movement of the grip element 45 toward the axis of the handle 48, and the arrangement is such, hydraulically, that a predetermined initial pressure must be exerted on the grip element 45 in. 'order to eifect an initial displacement of the fluid to actuate the gage. The gage 5i, as in the previously-described structure, is calibrated to indicate fluid displacement in terms of inchpounds pressure applied to the grip element 45 toeffect such displacement. The grip element 45 is retained on the body 44 by a chain 45* (Fig. 5) connected at one end to the grip element and at the other end to the body 44. This chain limits the outward displacement movement of the piston like supports 46 and 4'! and, in turn, the outermost or normal, at-rest position of the grip element 45. Other than above described, the structure and operation of this form of my invention is substantially the same as the firstdescribed form. That is, when the wrench is applied to the work and is moved clockwise (Fig. 5) to tighten the work, and the work oilers suflicient resistance to eiiect a displacement of the fluid in chambers 48 and 48, the grip element 45 will move toward the handle displacing the fluid, and the extent of this displacement will depend upon the amount of force or torque applied through thewrench.

:It is believed that the operation and advantages of my invention will be well understood .crank shaft or a spindle, or the like, thereby determining whether or not the rotating parts'are initially properly fitted together.

It is to be understood that, although I have shown and described two forms of structure emtion as defined by the claims that follow. Forto give way upon the application of pressure to handle and adapted to engage the work, a hand bodying my invention, other changes in details and arrangements of parts may be resorted to without departing from the scope 01 my invenexample, if desired, the grip unit may be arranged so as to be detachably connected, as a unit, to the wrench handle so that the wrench may beused with or without the torque measuring function. In other'words, the grip unit may take the form of a wrench accessorywhich may be readily applied to wrench structures already in use.

I claim:

1. A torque measuring wrench comprising a handle, means associated with 'one end of said handle and adapted to engage the-work, a hand 'grip unit on said handle at a point removed from said means, said unit including a grip element,

toward said handle, and means for. measuring the extent of movement of said grip element in terms of pressure applied to the wrench through said grip element.

2. A torque measuring wrench comprising a handle, means associated withone end of said handle and adapted to engage the workfia hand grip unit on said handle at a point removed from said means, said unit including grip elements on diametrically opposite sides of the axis of said handle, means for mounting said grip elements on said handle for movement toward and from the axis of said handle including spaced apart members connected to both said elements and passing through said handle at substantially right angles to the axis thereof in a plane at substantially right angles to the axis of the work, and means opposing movement of the grip elements toward said handle and adapted .to give way upon the application of pressure to the grip elements, and means for measuring the extent of vmovement of said grip elements in terms of pres-.

sure applied to the wrench through the grip elements.

grip member on said body portion for movement toward and fromthe axis of said body portion including spaced apart support members secured to said grip member and slidably passing through said body portion at substantially right angles to the axis of said handle; and means carried by said body portion opposing slide movement of said support members to move said grip member toward theaxis of said body portion and adapted said gr ip member, and means for measuring the extent of movement of said grip member and adapted to register in terms of pressure the force or torque applied to the wrench through the grip member. v

4, A- torque measuring wrench comprising a handle-means associated with one end of said grip unit on said handle at a point removed from said means, said unit'including a body member,

a grip member, means for mounting said grip member on said body member for movement toward and from the axis of said handle including a support member mounted for slidemovement in said body member and at substantially right angles to the axis of said handle, and a spring disposed between said grip member and'said body member yieldably opposing movement of the grip member toward said body member and adapted to be compressed upon the application of pressure to the grip member, and means for measuring the extent of movement of said grip member as permitted by said spring in terms of pressure applied to the wrench through said grip member.

5. A torque measuring wrench comprising av handle, means associated'with one end of said handle and adapted to engage the work, a hand grip unit on said handle at a point removed from said means, said unit including a body member, a pair of, diametrically opposed grip members, common means for mounting both of said grip members on said body member for movement toward and from the axis of' said handle including a support member slidably engaged with said body member and secured at its opposite ends to said grip members, and a spring associated with said support member and'disposed between each said grip member and said body member for yieldably opposing movement of each of said grip members toward said body'member, and means for measuring the extent of movement of both said grip members toward said body mem her in terms of pressure applied "to the wrench through said grip members to effect movement of said grip members.

'6. A torque measuring wrench comprising a handle,'me'ans associated with one end of said handle and adapted to engage the work, a hand grip unit on said handle at a point removed from said means, said unit including grip members on opposite sides of the axis of said handle, means for mounting said grip members on said handle for slide movement toward and from the axis of said handle, and spring members disposed between said grip members and said handle on the opposite sides of the axis of the latter for opposing movement of said grip members toward said handle and adapted'to be compressed upon application of pressure tomove the grip members toward the handle, and gage means for measuring the extent of movement of said grip members in terms of pressure applied to the wrench rotatably in opposite directions through ,said grip members comprising a rack connected to said grip members preventing movement of the same toward each othena pinion in engagement with said rack, a hand'mounted on said pinion, and a scale member for indicating -the, extent-of rotative movement of said hand.

'7. A torque measuring wrench comprising a handle, means associated with one end ofsaid -means opposing slide movement of said piston member toward the axis of said handle and adaptedto be displaced uponthe application of pressure to the grip member, and means for measm'ing the amount of displacement of said hydraulic means in terms of pressure applied to the wrench through the grip member.

8. A torque measuring wrench comprising a handle, means associated with one end of said handle and adapted to engage the work, a hand grip unit on said handle at a point removed from said means, said unit including a body portion having spaced piston chambers therein, a grip member, pistons on said grip member operatively engaged in said chambers for supporting said grip member for movement toward and from the axis of saidhandle, mechanism for registering the amount of displacement of fluid in terms of units of pressure, said body portion having eways connecting said chambers and said registering mechanism, said chambers and said passageways being filled with a hydraulic-acting fluid adapted to be displaced by the application of pressure upon said grip member so as to actuate said registering mechanism.

HERMAN W. ZIMMERMAN. 

